The problem with some who homeschool is the same as the problem with some who use public schools, which is the same as the problem with every human being: Taking responsibility. To take responsibility for your children's education does not mean simply disenrolling them from public school. That may be a first step, but there are ten thousand more steps after that. People want to check something off their checklist and have it done with. For many things, that works. For educating your child, it does not.
Homeschooling is not a discrete activity. Homeschooling is best described as a lifestyle. Life itself becomes the school. Topics are not taught individually, divorced from their application in life; rather, the child is introduced to life's tasks and wonders in the context of the skills being taught, e.g. math.
There are those who listen to people (like me, perhaps) who decry the state of public education and suggest that homeschooling might be the best possible alternative. Those people, in a fit of pique, might then pull their children from the public schools. This in itself is not bad, and could be the first step to something good. But again, steps 2 through 10,001 must be taken, or the children are little better off than they were, and in at least some cases are actually worse off.
Homeschooling is not an event. Homeschooling is a lifestyle choice. You don't have to be perfect at it, just as you don't have to be perfect at any life choice you make, at least to begin with. You simply need to be dedicated to the tasks before you and humble enough to see when you're wrong or don't know what you're doing and get help. In my view, what we call "homeschooling" is really just family and friends taking care of each other, the way God intended us to live. If you give honest effort, you will very probably be okay and your children will benefit greatly from your sacrifices. If you think you can simply hand the kids a book and the TV remote, your children will get few if any benefits from your efforts.
I'm an advocate and perhaps an evangelist for homeschooling. But implicit in that advocacy is the idea that you actually homeschool your children.